Fuse



Nov. 15, 1927. 1,649,561

R. S. BLAKE FUSE Filed Aug.18, 1920 Patented Nov. 15, 1927.

Unirse STAT-Es PATENT OFFICE.

ROBERT S. BLAKE, OF CHICAGO, ILLINOIS, ASSGNOR TO PERCE FUSE CORPORATION, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

FUSE.

Application led August 18, 1920. Serial No. 404,308.

This invention relates to that type of refillable fuse in which the casing is made up of two tubular sections slidable lengthwise upon one another for the purpose of opening and closing the same when renewing the fuse link on the terminals.

The object of this invention is to provide simple, eticient and inexpensive means for locking the casing sections in their closed position so that the same will not open accidentally or under the pressure of the gas which occurs during the blowing of a fuse link.

ln the accompanying drawings:

Figure 1 is a longitudinal section of my improved fuse taken at right angles to the plane of the terminals and fuse link. Figure 2' is a horizontal section taken on line 2--2, Fig. 1. Figures 3, e and 5 are cross sections taken 0n the correspondingly numbered lines in Figs. 1 and Figure 6 is an end view of the locking cap of the fuse.

Similar characters of reference refer te like parts throughout the several views. v

1n its preferred form the inclosing casing of the fuse comprises inner and outer tubular sections 10, 11, which lit oneinto the other and are adapted to slide lengthwise relatively to one another in the manner of a telescope for the purpose of opening and closing the fuse when introducing a fuse link 12 into the space or chamber within the casing. For permitting a fuse .link to be .iiitroduced into the casing the inner section thereof is provided in its side witha filling opening 13 through which the fuse is passed when this opening is uncovered by sliding the outer section from over the opening. The casing sections may be c oiistructed'of any suitable electric insulating material, such as vulcanite or libre.

14, 15 represent two metal outer end caps of cup-shaped form constructed of metal and mounted on the opposite ends of the casing sections with the concave sides facing each other. One of these caps, for instance the cap 11i, is secured to the outer casing section at one end thereof by suitably indenting the flange of this cap so that the indentation enters the outer casing section in the form of a spur, as shown at 16 in Figs. 1, Q, and 3, and thus compels this cap and casing section to move together. The other outer cap 15 has its flange fitted slidingly over theopposite end of the outer casing section, so that these parts can be separated lengthwise from each other and also pushed together for opening and closing the casing. Each of these outer caps is provided with a central terminal opening 27 having the form of a slot extending across the disk or plate of the respective cap. This disk of the cap 15 is provided with a vent opening 18.

19 represents two metal inner end bushings which are arranged in the opposite ends of the inner casing s ction and are constructed of cup-shaped form with their conver;` sides facing each other. 20, 201 represent two metal disks each of which I engages with the corresponding outer end of one of the bushings and is provided with vent openings 21 which normally register with those in the adjacent end cap. The disk 20 extends across the adjacent ends of the inner and outer casing sections and is secured by soldering or brazing to the adjacent cap 15, but the disk 201 is of smaller di-` ameter and extends only across the adjacent end of the inner casing section and is secured by brazing or otherwise to the adjacent terminal. The heads of the bushings are also provided with vent openings 22 which however are out of line with the vent openings in the caps and disks so that the flash of fire in the event of a fuse link blowing cannot pass in a straight course from the .interior of the casing to the exterior thereof. To further guard against any damage by lire from the fuse link a screen 23 of woven or gauze wire is arranged oiithe inner side of the disks 20, 201 so as to cover the openings therein, thereby preventing any flame from the blowing fuse from passing to the outer side of the casing.

24, 25, represent two terminals of flat metal which are connected by the fuse link and which are adapted to be connected with the contacts of a fuse block. The terminal 24 has a wide outer part or contact blade 26 which engages with the fuse block contact and is arranged in a slot 27 formed in the plate of the cap 11i and a narrow inner part or attaching shank 28 which extends through corresponding slots 29, 30 in the adjacent disk and head of the bushing 19 and terinii nating within the casing. The other terminal 25 has a wide outer part or blade 31 and a narrow inner part or shank S2 which projects through corresponding slots 33, 34 in the adjacent disk and bushing 19 and termi- (ill nates within the casing. The fuse link is detachably connected with the shanks 28 and 32 ot the terminals by shown, or any other suitable means. A pin 36 passes transversely through each bushing and the adjacent parts of the corresponding terminal and the adjacent end of the inner casing section for iirmly connecting these parts. The head'ot the cap 14 is provided with vent openings 39 which in the normal position of this cap are adapted to register with the openings -21 in the adjacent disk and permit the escape oit gas from the interior oi2 the casing when a fuse link blows.

The means for locking the outer casing section against accidental opening are constructed as follows:

Between the wide outer and the narrow inner part ot the terminal 24 the saine has a reduced part or neck 37 which is transversely in line with the head of the adjacent end cap 14 and the slot 27 therein and torms two inwardly facing shoulders 38 on opposite longitudinal edges of this ermiual The slot 27 in the head of the cap 14 is greater in length than the width of the outer part of the terminal 24 so that the latter is tree to slide through this slot. On diagonally opposite parts of the edge of the slot 27 the same is provided with recesses 40, the distance between the outer extremities ot which is less than the width of the wide outer part of the adjacent terminal but greater than the width of the neck 37 of the same, thereby forming locking lips 41 on this cap adj acent to the outer edges of the recesses 40. It Jfollows from this construction that when the cap 14 is placed so that its long slot 27 is in line with the terminal 24 then the outer casing section can be freely slipped length wise on and oil ot this terminal and the inner casing section for closing and opening the casing. Vhen the outer casing section has been moved fully inward into its closed position the head of its cap 14 is transversely .in line with the neck oit the respective terminal. Upon now turning this cap in the direction for bringing its locking lips 41 behind and in engagement with the shoulders 38 then this cap and the outer casing section associated therewith will be held against outward lengthwise movement relative to the to cover the space within the casing. For

means oi? bolts Sagas inner casing section and the terminals, so as unlocking the cap 14 and the outer casing section it is only necessary to turn this cap in the reverse direction so as 'to disengage the lips 41 from the shoulders 38 when this cap will be tree to be moved longitudinally Outward on the respective terminal ior uncovering the fuse inlet opening 13 of the casing. The outer' casing section and its cap are preferably so connected that they are compelled to turn and move lengthwise t0- gether but this is not necessarily so inasmuch as the advantages of my invention are present it these parts are not thus connected.

These means ttor locking the parts oi the casing in the closed position are very simple and low in cost, they can be operated easily and quickly and they hold the parts reliably in place so that accidents are avoided.

I claim as my invention:

A tuse having a casing provided with inner and outer tubular sections ot insulating material which are slidable lengthwise relatively to one another', said inner sect-ion having an opening in its side for the introduction of a fuse link into the casing, a flat terminal mounted on one end of the inner casing section and having outer and inner parts 4arranged outside and inside of the casing and having its Aouter part reduced to form a neck adjacent to the casing and producing inwardly facing shoulders at opposite edges thereof, and a cap mounted on the outer casing section so as to be movable lengthwise therewith and having its disk provided with a slot through which said terminal can move lengthwise and also provided on diagonal opposite parts of the edge of said slot with recesses, the distance between the outer extremities of which is greater than the width of said neck but less than the width of the outer part of the terminal and thereby forming lips on the adjacent parts of the disk which are adapted to engage with said shoulders.

ROBERT iS. BLAKE.

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